Mobile communication devices are becoming increasingly popular for business and personal use due to a relatively recent increase in number of services and features that the devices and mobile infrastructures support. Handheld mobile communication devices, sometimes referred to as mobile stations, are essentially portable computers having wireless capability, and come in various forms. These include Personal Digital Assistants (PDAs), cellular phones and smart phones. While their reduced size is an advantage to portability, bandwidth and processing constraints of such devices present challenges to the downloading and viewing of documents, such as word processing documents, tables and images. Also, as a result of their enhanced levels of functionality and computing power, handheld mobile communication devices are increasingly susceptible to attack by computer viruses.
Computer hackers commonly use email attachments as virus carriers to attack corporate network-connected computers. Therefore, email attachments are often identified as presenting a security threat for corporate networks. In order to protect such networks, many corporations and organizations use sophisticated systems to safely handle email attachments. One of the more common corporate approaches is to employ document management systems. One feature of such systems is that they usually rename email attachments with a common extension, for example “.tmp”.
When the user of a mobile device receives an email with renamed attachments it is difficult for the user to determine which attachment is of interest based on file names alone. For example, if a mobile device user receives an email with attachments named 0001.tmp, 0002.tmp and 0003.tmp, and only one of them is a MS WORD® document that is of interest, the user is unable to identify the document from the common file extensions. The normal recourse in such a situation is to retrieve the document contents for all attachments from the remote document server, and successively review the documents in order to identify the desired one.
However, the downloading of an entire document from the server to a mobile communication device consumes a large amount of bandwidth, especially when the document is large. In addition, viewing even a portion of such a downloaded document on the device consumes substantial device CPU/memory/battery resources.